Carbofuran Research Papers - Academia.edu (original) (raw)

- by
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- Arsenic, Adoption, DISTRIBUTION, Biodegradation

The dissipation of carbofuran from soils within the Nzoia River Drainage Basin in Kenya was studied under real field conditions for 112 days. Results showed significantly enhanced dissipation of carbofuran with half life (DT 50 ) values of 8 days (p = 0.038) in soils with prior exposure to carbofuran compared to 19 days in soils with no application history. At the end of the experiment, residues of 2.57 % and 9.36 % of the initial carbofuran applied were recorded in the two types of soil, respectively. Carbofuran metabolites identified in the study were 3-keto carbofuran and carbofuran phenol with 5.84 % and 15.0 % remaining in soils with prior exposure, respectively. Soils with no application history recorded 16.05 % and 12.82 % of 3-keto carbofuran and carbofuran phenol metabolites, respectively.

- by zachary Getenga and +1
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- Soil, Environmental Monitoring, Rivers, Kenya

The removal of 2,4-dichlorophenoxyacetic acid (2,4-D) and carbofuran from aqueous solution was studied by using fertilizer industry waste (carbon slurry) and steel industry wastes (blast furnace slag, dust, and sludge) as adsorbents in batch. Adsorption was found to be in decreasing order: carbon slurry, blast furnace sludge, dust, and slag, respectively. Carbonaceous adsorbent prepared from carbon slurry exhibited the uptake capacity of 212 and 208 mg g −1 for 2,4-D and carbofuran, respectively at 25 • C and pH 7.5. Adsorption equilibrium, kinetics, and thermodynamics were investigated as a function of initial pH, temperature, and pesticide concentrations. Equilibrium data fitted well to the Langmuir equilibrium model in the studied concentration range of 2,4-D and carbofuran at all the temperatures studied. Two simplified models, including pseudo-firstorder and pseudo-second-order kinetic models, were used to test the adsorption kinetics. Adsorption of 2,4-D and carbofuran on carbon slurry at 25, 35, and 45 • C could be best fitted in the pseudo-second-order kinetic model. Pore diffusion was confirmed as the essential rate-controlling step with the help of Bangham's equation.

- by Vinod Kumar Gupta
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- Engineering, Thermodynamics, Kinetics, Adsorption

In the current study, African catfish, Clarias gariepinus, was exposed to a sublethal concentration of carbofuran (CF) to investigate its negative effects on biochemical and oxidative stress biomarkers. Also, the putative role of lycopene (LYC) administration in alleviating these negative effects was evaluated. Fish were divided into six groups in triplicates as follows: group I was without treatment, group II was orally administered corn oil, group III was orally administered 18 mg LYC/ kg body weight, group IV was exposed to 0.121 mg CF/ L, group V was orally administered 9 mg LYC/kg body weight and exposed to 0.121 mg CF/L, and group VI was orally administered 18 mg LYC/kg body weight and exposed to 0.121 mg CF/L for 4 weeks. At the end of this period, blood and tissue (liver and kidney) samples were collected and biochemical and oxidative stress biomarkers were analysed. Also, histopathological changes were determined. Carbofuran caused significant increments of glucose, cortisol, aspartic amino transferase, alanine amino transferase, cholesterol, urea, and creatinine; meanwhile, serum acetylcholinesterase, total protein, albumin, and total lipids were significantly reduced. Significant increments in hepatic and renal malondialdehyde (MDA) and superoxide dismutase (SOD) levels and marked reduction in hepatic and renal catalase (CAT), glutathione (GSH), and total antioxidant capacity (TAC) levels were observed in CF-exposed fish comparing to the control group. Treatment with LYC attenuated the CF-induced oxidative stress, and this improvement was more pronounced in fish received the high LYC dose (18 mg/kg body weight). Further, congestion of the central vein with infiltration of mono-nuclear inflammatory cells, vacuolar necrosis, and haemorrhage was observed in the livers of CF-exposed fish. Oral administration of LYC reduced behavioural changes and histopathological alterations. All the altered biochemical parameters and antioxidant biomarkers were also restored to be near the normal levels. The obtained results evoked that LYC administration alleviated the destructive effects of carbofuran and reduced its toxicity effect on African catfish.

- by Heba Salah Hamed
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- Oxidative Stress, African Catfish, Lycopene, Fish histopathology

Effects of carbofuran commercial formulation on oxidative stress parameters were studied in carps (Cyprinus carpio) exposed to 50 mg/L for 7 and 30 days under rice field and laboratory conditions. Thiobarbituric acid reactive substance (TBARS) levels were increased in the brain of fish after 7 and 30 days under rice field and laboratory conditions. In the liver and muscle, TBARS levels increased after 7 and 30 days under laboratory conditions, whereas in rice field the levels increased only after 30 days. Protein carbonyl content in the liver increased after 7 and 30 days under both experimental conditions. Acetylcholinesterase (AChE) activity was decreased in the brain and muscle after 7 and 30 days under both experimental conditions evaluated. The superoxide dismutase (SOD) activity increased in the liver after 7 and 30 days under rice field condition, whereas under laboratory condition this enzyme increased only after 30 days. The catalase (CAT) activity in the liver decreased after 30 days under rice field condition, whereas no changes were observed under laboratory conditions. In rice field, glutathione S-transferase (GST) decreased after 7 days but increased after 30 days, whereas no change was observed in fish exposed to carbofuran under laboratory conditions. These results suggest that environmental relevant carbofuran concentrations may cause oxidative stress, affecting biochemical and enzymatic parameters on carps. Some parameters could be used as biomarkers to carbofuran exposure.

- by Bárbara Clasen
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- Toxicology, Biology, Oxidative Stress, Medicine

Adsorption equilibrium and kinetics of 2,4-dichlorophenoxyacetic acid (2,4-D) and carbofuran using
commercial granular activated carbon, Filtersorb 300 (GAC F300) were studied in a batch system with
respect to initial concentration of 2,4-D and carbofuran. The Langmuir and the Freundlich isotherm models
were applied to the equilibrium data of 2,4-D and carbofuran adsorption. Observed results showed that the
equilibrium data fitted well to the Langmuir equilibrium model in the studied concentration range of 2,4-D
and carbofuran. The monolayer adsorption capacities of GAC F300 were 181.82 and 96.15 mg/g for 2,4-D and
carbofuran, respectively. Two simplified models, pseudo-first order and pseudo-second order kinetic, were
used to test the adsorption kinetics of 2, 4-D and carbofuran on GAC F300. The data was best fitted to the
pseudo-second-order kinetic model

- by Bassim H Hameed
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- Adsorption, Activated Carbon, Pesticides, Carbofuran

The present study demonstrates EPS production by Cupriavidus sp. ISTL7 along with its capability to remediate a toxic carbamate pesticide, carbofuran. The strain ISTL7 efficiently degraded approximately 98% of carbofuran (400 ppm) within 96 h. GC-MS analysis showed catabolic metabolites of degradation which included carbo-furan-7-phenol, methylamine, 2-hydroxy-3-(3-methylpropan-2-ol)benzene-N-methyl-carbamate etc. EPS production from the mineral medium supplemented with carbofuran was observed to be 3.112 ± 0.3682 g L −1. FTIR confirmed its carbohydrate composition and the monomeric sugars: glucose, xylose, sorbitol and fructose were identified by GC-MS analysis. The toxic potential of degradation experiment and the produced EPS was evaluated on HepG2 (mammalian liver cell line). The cytotoxicity of carbofuran was reduced upon bacterial degradation and the formed EPS was found to be non-toxic as inferred from percentage cell viability. The present research can possibly influence the development strategies of biological remediation.

- by Rashmi Rathour
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- Toxicity, Microbial Degradation, Extracellular polymeric substances, Carbofuran

Carbofuran and malathion, well known pesticides, and paraquat, a world widely used herbicide, were tested on acetylcholinesterase (AChE) from Bungarus sindanus venom and butyrylcholinesterase (BChE) from human serum. The calculated IC 50 values for inhibition of venom enzyme by malathion, carbofuran and paraquat were 2.5, 0.14, and 0.16 lM, respectively. The values for inhibition of serum butyrylcholinesterase (BChE) were 3.5, 0.09 and 0.18 lM, respectively. Analysis of kinetic data indicated that the inhibition caused by malathion, carbofuran and paraquat was mixed for venom AChE. For BChE from human serum, the inhibition caused by malathion and paraquat was mixed and for carbofuran it was uncompetitive. The present results suggest a commercial paraquat preparation (a popular herbicide) inhibits cholinesterases with similar or higher potency than classical pesticide inhibitors. Furthermore, this inhibition was observed both in human serum and snake venom, a newly studied source of AChE.

- by Vera Morsch
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- Ecotoxicology, Kinetics, Snake venoms, Biological Sciences

Terrestrial avoidance behavior is proposed as a fast and cost-effective method for assessing effects of pesticides on earthworms. Tropical species however, have rarely been used in avoidance tests. Avoidance tests were performed with Perionyx excavatus, a tropical species, and Eisenia andrei as the standard species, using chlorpyrifos and carbofuran in artificial and natural soil. Earthworms were exposed to concentrations of 1-900 (chlorpyrifos) and 1-32 (carbofuran) mg a.i. kg À1 dry soil in a two-chamber system under tropical conditions (26 ± 2°C, 48 h). No significant difference was found in the control tests comparing the two soils used, suggesting soil type did not affect the distribution of the worms. The results suggest a higher sensitivity of E. andrei, with EC 50S for the effect on avoidance behavior for both pesticides being a factor of 2-3 lowers than for P. excavatus. Earthworm avoidance tests with local species should therefore be used with caution when applied as a tool for pesticide risk assessment in the tropics. Endpoints generated through avoidance tests in this study are shown to be less sensitive than reproduction and more sensitive than survival. This was further confirmed by literature data available. Earthworm avoidance tests therefore can only replace survival tests as an initial screening tool for risk assessment.

- by P. Mangala C.S De Silva
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- Soil, Animal Behavior, Environmental Monitoring, Risk assessment

In this work, activated carbon was prepared from banana stalks (BSAC) waste to remove the insecticide carbofuran from aqueous solutions. The effects of contact time, initial carbofuran concentration, solution pH and temperature (30, 40 and 50 • C) were investigated. Adsorption isotherm, kinetics and thermodynamics of carbofuran on BSAC were studied. Equilibrium data were fitted to the Langmuir, Freundlich and Temkin isotherm models and the data best represented by the Langmuir isotherm. Thermodynamic parameters such as standard enthalpy ( H • ), standard entropy ( S • ) and standard free energy ( G • ) were evaluated. Regeneration efficiency of spent BSAC was studied using ethanol as a solvent. The efficiency was found to be in the range of 96.97-97.35%. The results indicated that the BSAC has good regeneration and reusability characteristics and can be used as alternative to present commercial activated carbon.

- by Jasim Salman
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- Engineering, Thermodynamics, Kinetics, Water Purification
- by Mohd Sayeed and +1
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- Arecaceae, Biopesticides, Population Density, Trichoderma

Maize production in Benin, especially in resource-poor farmers' fields, is constrained by stemborers among other factors. One of the major stemborers in southern Benin is Sesamia calamistis Hampson (Lepidoptera: Noctuidae). African farmers cannot afford to use commercial insecticides for controlling stemborers - they are expensive and unsuitable for durable pest management systems due to eco-toxicity. There is therefore a need for cheaper and environmentally friendly methods and botanicals offer an attractive alternative. The bushmint, Hyptis suaveolens (L.) Poit. (Lamiales: Lamiaceae), was compared with the commercial insecticide Furadan (carbofuran) for the control of S. calamistis on maize Zea mays L. (Poales: Poaceae). Trials were conducted in the screenhouse and in the field during the minor cropping season in 2004 at the International Institute of Tropical Agriculture (IITA)-Benin station. The variables measured included numbers of egg masses per plant, eggs per egg mass ...

- by Kerstin Hell
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- Zoology, Pest Management, West Africa, Insecticides

Two new constituents, lantanoside (1) and lantanone (2), and the known compounds linaroside (3) and camarinic acid (4) were isolated from the aerial parts of Lantana camara. Compounds 1, 3, and 4 were tested for nematicidal activity against root-knot nematode Meloidogyne incognita and showed 90, 85, and 100% mortality, respectively, at 1.0% concentration. The results were comparable to those obtained with the conventional nematicide furadan (100% mortality at 1.0% concentration). Structures of the new compounds were elucidated by spectroscopic and chemical techniques.

- by Bina Siddiqui
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- Natural Products, Magnetic Resonance Spectroscopy, Flavonoids, Biological Sciences

A simple method was developed to determine carbofuran and 3-hydroxycarbofuran in coconut water. The procedure involved solid-phase extraction using C 18 cartridges with acetonitrile for elution. The analysis of these compounds was carried out by liquid chromatography with UV detection at 275 nm using a gradient solvent system. The method was validated with fortified samples at different concentration levels (0.01 -2.5 mg/mL). Average recoveries ranged from 81 to 95% with relative standard deviation between 1.6 and 12.5%. Each recovery analysis was repeated at least five times. Detection limits ranged from 0.008 to 0.01 mg/mL. The analytical procedure was applied to coconut water samples from palms submitted to treatment with commercial formulation under field conditions.

- by Haroldo Silveira Dórea
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- Engineering, Analytical Chemistry, Chromatography, Filtration

A rapid and simple method for the extraction and preconcentration of N-methylcarbamates (NMCs) (carbofuran, carbaryl and promecarb) in water samples using dispersive liquid–liquid microextraction (DLLME) using chemometrics was developed. Influence variables such as volume of extracting (CHCl3) and dispersing solvents (ACN), pH and ionic strength, extraction time and centrifugation time and speed were screened in a 27–4 Plackett–Burman design was

- by saeid khodadoust
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- Analytical Chemistry, Design, Chemometrics, Experimental Design

Using a 2 3 experimental design, liquid-liquid extraction with low temperature partitioning (LLE-LTP) was optimized and validated for analysis of three carbamates (aldicarb, carbofuran and carbaryl) in water samples. In this method, 2.0 mL of sample is placed in contact with 4.0 mL of acetonitrile. After agitation, the sample is placed in a freezer for 3 h for phase separation. The organic extract is analyzed by high performance liquid chromatography with ultraviolet detection (HPLC-UV). For validation of the technique, the following figures of merit were evaluated: accuracy, precision, detection and quantification limits, linearity, sensibility and selectivity. Extraction recovery percentages of the carbamates aldicarb, carbofuran and carbaryl were 90%, 95% and 96%, respectively. Even though extremely low volumes of sample and solvent were used, the extraction method was selective and the detection and quantification limits were between 5.0 and 10.0 g L −1 , and 17.0 and 33.0 g L −1 , respectively.

The aim of the present study is to contribute an ecologically relevant assessment of the ecotoxicological effects of pesticide applications in agricultural areas in the tropics, using an integrated approach with information gathered from soil and aquatic compartments. Carbofuran, an insecticide/nematicide used widely on sugarcane crops, was selected as a model substance. To evaluate the toxic effects of pesticide spraying for soil biota, as well as the potential indirect effects on aquatic biota resulting from surface runoff and/or leaching, field and laboratory (using a cost-effective simulator of pesticide applications) trials were performed. Standard ecotoxicological tests were performed with soil (Eisenia andrei, Folsomia candida, and Enchytraeus crypticus) and aquatic (Ceriodaphnia silvestrii) organisms, using serial dilutions of soil, eluate, leachate, and runoff samples. Among soil organisms, sensitivity was found to be E. crypticus < E. andrei < F. candida. Among the aqueous extracts, mortality of C. silvestrii was extreme in runoff samples, whereas eluates were by far the least toxic samples. A generally higher toxicity was found in the bioassays performed with samples from the field trial, indicating the need for improvements in the laboratory simulator. However, the tool developed proved to be valuable in evaluating the toxic effects of pesticide spraying in soils and the potential risks for aquatic compartments. Environ.

- by José Sousa
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- Soil, Brazil, Ecology, Agriculture

The objective of this study was to investigate the acute effects of the pesticide carbofuran on the sea bass (Dicentrarchus labrax) using parameters at different levels of biological organisation (swimming behaviour and several biomarkers) and possible relationships between alterations found in different effect criteria. In a bioassay, sea bass juveniles were individually exposed to different doses of carbofuran (31, 63, 125 and 250 μg/L) for 96 h. At the end of the bioassay, the swimming performance and 11 biomarkers were determined. Biomarkers were: hepatosomatic index (HSI), lipid peroxidation (LPO), reduced glutathione and the activities of the enzymes ethoxyresorufin O-deethylase (EROD), glutathione S-transferases, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, brain acetylcholinesterase (AChE) and muscle cholinesterases (ChE). After 96 h of exposure, carbofuran induced a decrease of the swimming velocity and inhibition of EROD activity at all concentrations tested, and inhibition of muscle ChE and brain AChE activities at 250 μg/L. No relevant alterations in any of the other tested parameters were found. These results show that carbofuran induced adverse effects on fish by interfering with neurofunction, capability of detoxication and swimming velocity. In addition, positive and significant correlations between the swimming velocity and (i) brain AChE activity, (ii) muscle ChE activity and (iii) EROD activity suggest that the inhibition of these enzymes may somehow be related to the behavioural changes observed. Since these functions are determinant for the survival and performance of the fish in the wild, the findings of the present study suggest that adverse effects may occur in populations exposed to carbofuran if a sufficient number of animals is affected.► Acute effects of the pesticide carbofuran on the sea bass. ► Swimming performance and 11 biomarkers were determined. ► Carbofuran induced a decrease of swimming velocity and inhibition of EROD activity. ► Inhibition of muscle ChE and brain AChE activities at 250 μg/L.

- by Francisco Soler
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- Ecotoxicology, Swimming, Environmental Sciences, Pesticides

A selective and simple analytical method for the trace level determination of carbofuran in complex environmental and biological samples was developed based on immunoaffinity extraction (IAE) followed by on-line preconcentration and HPLC/UV analysis of the purified extract. The immunosorbent for IAE was prepared by sol-gel encapsulation of monoclonal anti-carbofuran antibodies, and was fully characterized for capacity, repeatability, binding strength, binding kinetics and cross-reactivity. Method performance was evaluated with two different types of difficult samples: dam water and methanolic extracts of epithelial cervical-uterine tissue. Linear behavior and quantitative recoveries were obtained from the analysis of samples spiked with carbofuran at 0.2-4 ng/mL (dam water, 50 mL samples) and 10-40 ng/mL (biological tissue extract, 2 mL samples). RSD (n = 7) and detection limits were, respectively, 10.1% (spike 0.40 ng/mL) and 0.13 ng/mL for dam water; 8.5% (spike 20 ng/mL) and 5 ng/mL for the biological tissue extract. The excellent sample purification achieved with the IAE column allows precise and accurate determination of carbofuran in complex matrices, even when using non-selective UV detection in the chromatographic analysis.

- by Gustavo Zelada-Guillen
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- Materials Engineering, Chemical Engineering, Materials Science, Chemistry
- by Mutuku Mwanthi
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- Environmental Monitoring, Kenya, Insecticides, DDT

The acute effect of carbofuran, a carbamate insecticide, was studied on adenosine triphosphatase enzymes in gill, kidney, liver and muscle tissues of a food fish, Clarias batrachus. Glycogen and glycogen phosphorylase were investigated in gill and kidney only. Thirty-six fish were exposed to sublethal concentration (7.6 mg/L) for 6 days. After 6 days, 18 fish were released into freshwater in order to study the recovery response. Eighteen fish were kept in clean water as control. Tissues were isolated from control, exposed and recovery fish at the end of 1, 3 and 6 days and used for the assay of enzymes. Total ATPase was inhibited in kidney and muscle tissues throughout the exposure period, whereas branchial and hepatic tissues showed initial induction followed by inhibition. Na ? -K ? ATPase activity was induced in gill till day 3, whereas in other tissues inhibition was throughout the exposure period. Mg ?2 ATPase activity was inhibited in all tissues except liver. When the fish were released into freshwater, liver recovered almost to control values and other tissues showed organ-specific response. Glycogen content of gill increased initially followed by decrease, and in kidney initial decrease was noted. The recovery response was more in kidney than in gill. Induction in the activity of glycogen phosphorylases was observed in kidney, whereas gill tissue showed mixed response. Recovery was not observed in phosphorylases. Thus, the results of the present study demonstrated the acute effect of carbofuran on a food fish and organ-specific recovery response to insecticidal treatment.

- by Ghousia Begum
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- Ecology, Insecticides, Kidney, Liver

- by Sónia Chelinho
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- Soil, Brazil, Ecology, Agriculture

Amperometric acetylcholinesterase biosensors have been developed for quantification of the pesticides carbofuran, carbaryl, methylparaoxon, and dichlorvos in phosphate buffer containing 5% acetonitrile. Three different biosensors were built using three different acetylcholinesterase (AChE) enzymes-AChE from electric eel, and genetically engineered (B394) and wild-type (B1) AChE from Drosophila melanogaster. Enzymes were immobilized on cobalt(II) phthalocyanine-modified electrodes by entrapment in a photocrosslinkable polymer (PVA-AWP). Each biosensor was tested against the four pesticides. Good operational stability, immobilisation reproducibility, and storage stability were obtained for each biosensor. The best detection limits were obtained with the B394 enzyme for dichlorvos and methylparaoxon (9.6× 10 −11 and 2.7× 10 −9 mol L −1 , respectively), the B1 enzyme for carbofuran (4.5×10 −9 mol L −1 ), and both the B1 enzyme and the AChE from electric eel for carbaryl (1.6×10 −7 mol L −1 ). Finally, the biosensors were used for the direct detection of the pesticides in spiked apple samples.

- by Totan Adak
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- Engineering, Soil, Kinetics, Nanoparticles

Controlled release (CR) formulations of azadirachtin-A, a bioactive constituent derived from the seed of Azadirachta indica A. Juss (Meliaceae), have been prepared using commercially available polyvinyl chloride, polyethylene glycol (PEG) and laboratory synthesized poly ethylene glycol–based amphiphilic copolymers. Copolymers of polyethylene glycol and various dimethyl esters, which self assemble into nano micellar aggregates in aqueous media, have been synthesized. The kinetics of azadirachtin-A, release in water from the different formulations was studied. Release from the commercial polyethylene glycol (PEG) formulation was faster than the other CR formulations. The rate of release of encapsulated azadirachtin-A from nano micellar aggregates is reduced by increasing the molecular weight of PEG. The diffusion exponent (n value) of azadirachtin-A, in water ranged from 0.47 to 1.18 in the tested formulations. The release was diffusion controlled with a half release time (t1/2) of 3.05 to 42.80 days in water from different matrices. The results suggest that depending upon the polymer matrix used, the application rate of azadirachtin-A can be optimized to achieve insect control at the desired level and period.

- by Mukesh Singh
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- Engineering, Soil, Kinetics, Nanoparticles

To better understand the environmental fate of pesticides in Sri Lankan soils, we studied the sorption behavior of two commonly used pesticides (carbofuran and diuron) in 43 surface soils representing a range of soil physicochemical properties from dry and wet zones of Sri Lanka. For carbofuran, the K d (L/kg) values varied from 0.11 to 4.1 (mean, 0.83; median, 0.62) and K oc ranged from 7.3 to 120.6 (mean, 41.65; median, 36.1), whereas for diuron K d values varied from 0.5 to 75 (mean, 9.6; median, 5.15) and K oc ranged from 55.3 to 962 (mean, 407; median, 328). A comparison of sorption data on these tropical soils with published studies (mostly European and north American soils) showed that the ranges of sorption coefficients from Sri Lankan soils were within the wide range of K oc values reported in the literature. However, these values for both pesticides in soils from dry zones of Sri Lanka were consistently higher (up to two times) than those from the wet zone. The wide range of K oc values in Sri Lankan soils may be due to the possible difference in the nature of soil organic carbon, which needs to be further investigated.

- by Ransilu Watawala
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- Engineering, Physical Chemistry, Soil, Kinetics

A gas chromatography-tandem mass spectrometric (GC-MS/MS) method has been developed for the determination of carbofuran (2,3-dihydro-2,2-dimethylbenzofuran-7-yl methylcarbamate), carbaryl (1-naphthyl-N-methylcarbamate) and their main metabolites in human blood plasma. Optimization of the isolation of the compounds from plasma matrix included the precipitation, denaturation and digestion of plasma proteins. Derivatization was achieved by the use of trifluoroacetic acid anhydride and was optimized for temperature, time and volume of derivatization agent. In the proposed method, a mild precipitation technique was applied using β-mercaptoethanol and ascorbic acid in combination with solidphase extraction technique using Oasis HLB (Hydrophobic Lipophilic Balance) cartridges for further clean up of samples. Carbamate linkage was not hydrolyzed to its phenol product, but both carbamate phenol and ketones were transformed into trifluoroacetyl derivatives in order to become volatile compounds and were determined using tandem mass spectrometry. The linearity of the method was shown for nine concentrations in the range of 0.50-250 ng mL −1 in fortified plasma aliquots. Limits of detection (LODs) for all compounds ranged from 0.015-0.151 ng mL −1 . Inter-day and intra-day assays (RSD) for all com-pounds, at three concentration levels of 2.5, 25 and 100 ng mL −1 (n=3) in fortified plasma samples were less than 18%. Accuracy (%E r ) was calculated at three concentration levels, 8, 80 and 160 ng mL −1 (n=3), and ranged from −12.0 to 15.0%. Matrix effect was evaluated so mean recoveries were calculated for all compounds and ranged from 81-107%. Specificity for the use of this method to biological monitoring studies was achieved including four main metabolites of CF, 1-naphthol and 2-naphthol from the naphthalene metabolism pathways, and both the parent compound of carbofuran and carbaryl. The proposed method was applied to plasma samples of pesticide users.

- by Syrago-Styliani Petropoulou
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- Engineering, Mass Spectrometry, Agriculture, Optimization

The objective of this study was to investigate the acute effects of the pesticide carbofuran on the sea bass (Dicentrarchus labrax) using parameters at different levels of biological organisation (swimming behaviour and several biomarkers) and possible relationships between alterations found in different effect criteria. In a bioassay, sea bass juveniles were individually exposed to different doses of carbofuran (31, 63, 125 and 250 mg/L) for 96 h. At the end of the bioassay, the swimming performance and 11 biomarkers were determined. Biomarkers were: hepatosomatic index (HSI), lipid peroxidation (LPO), reduced glutathione and the activities of the enzymes ethoxyresorufin O-deethylase (EROD), glutathione S-transferases, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, brain acetylcholinesterase (AChE) and muscle cholinesterases (ChE). After 96 h of exposure, carbofuran induced a decrease of the swimming velocity and inhibition of EROD activity at all concentrations tested, and inhibition of muscle ChE and brain AChE activities at 250 mg/L. No relevant alterations in any of the other tested parameters were found. These results show that carbofuran induced adverse effects on fish by interfering with neurofunction, capability of detoxication and swimming velocity. In addition, positive and significant correlations between the swimming velocity and (i) brain AChE activity, (ii) muscle ChE activity and (iii) EROD activity suggest that the inhibition of these enzymes may somehow be related to the behavioural changes observed. Since these functions are determinant for the survival and performance of the fish in the wild, the findings of the present study suggest that adverse effects may occur in populations exposed to carbofuran if a sufficient number of animals is affected.

- by Francisco Soler and +1
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- Ecotoxicology, Swimming, Environmental Sciences, Pesticides

The bioavailability of carbofuran to the compost worms Eisenia andrei and the influence of its residual amounts on the avoidance, reproduction and growth of this species were studied in two natural tropical soils: a Typic Humaquept (GM) and a Typic Hapludox (LVD), as indicated by the Brazilian environmental authorities for ecotoxicological tests. The worms avoided the soil LVD treated with different doses of carbofuran. The pesticide also affected the production of juvenile specimens in both soils, but cocoon production was reduced only in the GM soil. The earthworms' growth and weight loss were affected by carbofuran (2,2-dimethyl-2,3-dihydro-1-1-benzofuran-7-yl methylcarbamate. CAS number 1563-66-2) only in the LVD and the mortality detected at 56 days of contact with the treated soils was not statistically significant in both of them. Fourteen days after the soil treatment with(14) c-carbofuran, most residues detected in the soils were bound residues (approximately 36% and 30...

- by Mara M. de Andréa
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- Chemistry, Ecotoxicology, Reproduction, Brazil

Chlorpyrifos ethyl was found to be widely distributed in water and sediment in Lake Naivasha. Higher levels were reported in sediment (11.2-30.0 ng g-1 dry weight (dw) in wet season than in dry season (4.7-17.4 ng g-1 dw). The mean concentration of chlorpyrifos ethyl in water in wet season ranged between 8.8 and 26.6 lg L-1 and decreased to between below detection limit to 14.0 lg L-1 in dry season. On average, higher concentrations of chlorpyrifos ethyl were observed in sediment than water samples. Statistical analysis revealed a significant difference in concentration between the seasons, and a significant interaction between seasons and mean concentrations at p B 0.05. However, levels of diazinon and carbofuran were below the detection limit in all the samples analyzed. Notably, levels of chlorpyrifos ethyl were higher than the maximum allowable limits (0.1 lg L-1) recommended by European Union for drinking water and general water quality criterion for protection of freshwater water organisms (0.083 lg L-1).

- by Peter Otieno
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- Environmental Monitoring, Kenya, Pesticide Residues, Insecticides

The long-term toxic effects of continuous exposure for 6 months, from January to June, to a safe dose (4.5 ppm) of a commercial carbamate pesticide, carbofuran, on the histophysiology of thyroid in adult and young (yearling) Channa punctatus, are described in this investigation. In both the experimental groups, thyroid histology exhibited various abnormalities, including hypertrophy, hyperplasia and degeneration of follicular epithelial cells, and reduction in colloid content. Apart from this, in young experimentals, fibrosis of thyroid components, formation of cystic cellular masses, and rupture of blood vessels resulting in hemorrhage can also be seen and suggest direct action of this pesticide on the thyroid. On the other hand, in both treated groups, retardation ofthyroid function was also evidenced by significantly reduced thyroidal radioiodine ("'I) uptake and CR (conversion ratio of PB 13'1 in blood serum in relation to total serum 13'1 uptake) values. Apparently, these histopathological and physiological changes were markedly pronounced in young experimentals, suggesting greater susceptibility of this group to chronic toxicity of carbofuran than that of adults. Thus, on the basis of these results, it can be inferred that carbofuran pesticide, which is washed into water systems in small quantities, induces adverse histophysiological alterations in thyroid, in an age-and size-dependent manner, possibly by acting directly on thyroid and/or through the hypothalamo-pituitary-thyroid axis, in this species.

- by Dr Raj Kishore Ram
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- Aging, Body, Insecticides, Environmental Sciences

This work investigated the effect from exposure to insecticides carbofuran and deltamethrin on acetylcholinesterase (AChE) activity in the brain and muscle of common carp (Cyprinus carpio). Both pesticides were evaluated through two separate experiments, and carp were exposed in a semi-static system to three different concentrations of carbofuran (10, 50, and 100 lg/L) and deltamethrin (0.08, 0.4, and 0.8 lg/L) during a month with sampling times at 0, 4, 15, and 30 days (n 5 7 from each aquarium). AChE activity was significantly inhibited in both organs of carps exposed to carbofuran at all sampling times depending on dose and time, reaching inhibition values of 73.5 and 67.1%, in brain and muscle tissues respectively, after 30 days with the highest concentration. On the contrary, AChE activity was not significantly affected after deltamethrin exposure at all concentrations and times of the assay. This study shows that the measurement of brain and muscle AChE activity in Cyprinus carpio is a useful biomarker of carbamates exposure and/or effects, but has no application with pyrethroids.

- by Francisco Soler
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- Environmental Toxicology, Biomarkers, Biological Sciences, Insecticides
- by H. Bouwman
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- Reproduction, Southern Africa, Insecticides, Environmental Sciences

The detection of trace levels of paraoxon and carbofuran was achieved utilizing differential pulse voltammetry (DPV) on gold disposable electrochemical printed (DEP) chips. The nanostructured gold surface of the chips enables highly sensitive oxidation of the thiocholine (TCh) product even in the absence of costly surface modifications. The inhibition of AChE activity at varying insecticide concentrations was detected with low detection limits of 10 ppb (36 nM) for paraoxon and 8 ppb (18 nM) for carbofuran. Fine-tuning of the experimental conditions will allow for the application of unmodified DEP gold chips for inexpensive on-field detection of AChE inhibition by various insecticides at or below the allowable concentrations set by European and North American regulation standards.

- by Holger Schulze
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- Analytical Chemistry, Electrochemistry, Nanomaterials, Insecticides

In this study, the cladoceran Daphnia magna was exposed to two model organophosphorous and one carbamate pesticides including malathion, chlorpyrifos and carbofuran to assess acetylcholinesterase (AChE) and carboxylesterase (CbE) inhibition and recovery patterns and relate those responses with individual level effects. Our results revealed differences in enzyme inhibition and recovery patterns among the studied esterase enzymes and pesticides. CbE was more sensitive to organophosphorous than AChE, whereas both CbE and AChE showed equivalent sensitivities to the carbamate carbofuran. Recovery patterns of AChE and CbE activities following exposure to the studied pesticides were similar with 80–100% recoveries taking place 12 and 96 h after exposure to organophosphorous and carbamates pesticides, respectively. The physiological role of AChE and CbE inhibition patterns in Daphnia was examined by using organophosphorous and carbamate compounds alone and with specific inhibitors of CbE. Under exposure to organophosphorous pesticides, survival of Daphnia juveniles was impaired at AChE inhibition levels higher than 50% whereas under exposure to the carbamate carbofuran low levels of AChE inhibition affected mortality. Inhibition of CbE by 80–90% increased toxicity to organophosphorous and carbamate pesticides by up to two- and four-fold, respectively. Our results suggest that both AChE and CbE enzymes are involved in determining toxicity of Daphnia to the studied chemicals and that AChE inhibition levels higher than 50% can be considered of environmental concern to Daphnia species.

- by Carlos Barata
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- Kinetics, Aquatic Toxicology, Daphnia, Biological Sciences
- by Ismail Sahid
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- Soil, Malaysia, Environmental Monitoring, Adsorption

We measured the effects in vitro of pure and commercial pesticides on Ca -activated ATPase and cholinesterase 2q (ChE) activities in the nervous system of the slug Phyllocaulis soleiformis. The pesticides used in this study included carbamate and organophosphates, which acts as reversible and irreversible anticholinesterases, respectively. Both enzymes were insensitive to pure carbofuran (1 mM), glyphosate (1 mM) and malathion (120 mM). However, the carbamate carbofuran, in the commercial formulation Furandan 350S, inhibited ATPase and ChE activities. The organophosphate glyphosate used in the commercial preparation of Gliz 480CS inhibited ATPase activity and increased cholinesterase ᭨ activity. These effects are likely due to the action of adjuvant substances of the chemical formulation. The commercial formulation (Malatol 500CE) did not alter enzymes activities. Our results suggest that cholinesterase present in the slug nervous tissue has a different behavior to those identified in vertebrate nervous tissue, since it was insensitive to pure compounds, known as anticholinesterases in vertebrates. Considering the insensitivity of the Ca -activated ATPase, we 2q suggested that the purinergic neurotransmission and other roles of ATP might not be affected by the pure pesticides tested. ᮊ

- by Flávia V Thiesen and +2
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- Enzyme Inhibitors, Biological Sciences, Environmental Sciences, ATPase
- by Marina Dellagreca and +1
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- Kinetics, Daphnia, Rotifera, Biological Sciences

Field experiment was conducted in the early and late planting season of 2009 and 2010 at Akampa and Bekwarra to evaluate the effects of carbofuran, a synthetic insecticide, Neem and Gmelina seed powder on maize agronomic characters in maize stem borer endermic zones. The treatments consisted of 2 levels carbofuran (1.0 and 1.5kga.i/ha) and 2 levels each of neem and Gmelina arborea seed powder (20 and 30kg/ha). The treatments were laid out in a randomized complete block design (RCBD) with 3 replications. Data collected included stem borer population per plant, plant heights at six (6) and eight (8) weeks after planting, and grain yield. Carbofuran and Neem seed powder significantly increased plant height and yield while Gmelina seed powder application significantly (P≤0.05) reduced maize growth and yield. The treatments significantly reduced borer population compared with control. It is possible that the neem powder at 30kg/ha may be used as a boost to maize development outside its insecticidal properties on maize used by resource poor farmers.

- by Simon Okweche
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- Agronomy, Biology, Carbofuran

Water quality assessment was conducted on the Ruiru River, a tributary of an important tropical river system in Kenya, to determine baseline river conditions for studies on the aquatic fate of N-methyl carbamate (NMC) pesticides. Measurements were taken at the end of the long rainy season in early June 2013. Concentrations of copper (0.21-1.51 ppm), nitrates (2.28-4.89 ppm) and phosphates (0.01-0.50 ppm) were detected at higher values than in uncontaminated waters, and attributed to surface runoff from agricultural activity in the surrounding area. Concentrations of dissolved oxygen (8-10 ppm), ammonia (0.02-0.22 ppm) and phenols (0.19-0.83 ppm) were found to lie within normal ranges. The Ruiru River was found to be slightly basic (pH 7.08-7.70) with a temperature of 17.8-21.2°C. The half-life values for hydrolysis of three NMC pesticides (carbofuran, carbaryl and propoxur) used in the area were measured under laboratory conditions, revealing that rates of decay were influenced by t...

- by Samuel Maina Njoroge
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- Environmental Science, Chemistry, Water quality, Rivers
- by William Draper
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- Environmental Science, Pesticide Residues, Medicine, Insecticides

In the present day world, environmental problems are multiple and complex, especially those arising from the disposal of hazardous materials. Therefore, the most urgent need at present is to identify and assess the toxicity of such substances. Assessment of human exposure to pesticides and other toxicants through biological monitoring offers one means to evaluate the magnitude of potential health risk

- by Vijay Bhatnagar
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- Chemistry, Medicine, Insecticides, DDT
- by Peter Otieno
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- Chemistry, Soil, Agriculture, Rivers

Biodegradation of carbamates and carbamothioates by microorganisms in soil has been widely reported; however, the ecology of pesticidedegrading microorganisms in soils and plant rhizospheres containing these pesticides has received less attention. Some bacteria capable of carbofuran (2,3-dihydro-2,3-dimethyl-7-benzofuranyl methyl carbamate) biodegradation in soil have been isolated and identified (Felsot et al. 1981 ; Chaudhry and Ali 1988). Reed et a1.(1987) identified several fungi and bacteria from soils with histories of pesticide application and observed that bacteria were able to metabolize the pesticides in pure culture more efficiently than were fungi. Bacteria and actinomycetes from soils with histories of carbamothioate herbicide use were found to utilize carbamothioates more efficiently than were isolates from nonhistory soils (Mueller et al. 1989). Lee (1984) found that biodegradation of EPTC (Sethyl dipropyl carbamothioate) was significantly affected by soil fungi. Interestingly, after storage bacterial isolates lost the ability to degrade EPTC. He concluded that fungi able to degrade EPTC may retain this ability in soil longer than do bacteria. Recent studies demonstrated that fungi along with bacteria detoxify herbicide wastes during bioremediation of contaminated soils (Felsot and Dzantor 1990).

- by Robert Kremer
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- Biology, Agriculture, Fungi, Medicine

The objective of this study was to investigate the feasibility of an in situ phytotoxicity test using alginate-immobilized algae for 60 days, in the assessment of water quality in an impacted small peri-urban stream. After laboratory optimization of algae immobilization/de-immobilization processes, the performance of immobilized/de-immobilized algae was compared to the performance of free algae in terms of specific algal growth and sensitivity. This was done by comparing 72 h EC50 values obtained with zinc and the pesticides clomazone and carbofuran. The results showed a similar performance, which allow us to conclude that immobilization for 60 days do not cause any significant alteration in algae physiology. In the field, immobilized algae were exposed at different times (2, 4 and 7 days) to water samples in both disturbed and undisturbed sites. Both laboratory and field experiments indicated that alginate-immobilized algae for 60 days were sufficiently sensitive for use in the in ...

- by Rogério Corrêa
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- Water quality, Ecotoxicology, Brazil, Environmental Monitoring

The objective of this study was to investigate the acute effects of the pesticide carbofuran on the sea bass (Dicentrarchus labrax) using parameters at different levels of biological organisation (swimming behaviour and several biomarkers) and possible relationships between alterations found in different effect criteria. In a bioassay, sea bass juveniles were individually exposed to different doses of carbofuran (31, 63, 125 and 250 mg/L) for 96 h. At the end of the bioassay, the swimming performance and 11 biomarkers were determined. Biomarkers were: hepatosomatic index (HSI), lipid peroxidation (LPO), reduced glutathione and the activities of the enzymes ethoxyresorufin O-deethylase (EROD), glutathione S-transferases, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, brain acetylcholinesterase (AChE) and muscle cholinesterases (ChE). After 96 h of exposure, carbofuran induced a decrease of the swimming velocity and inhibition of EROD activity at all concentrations tested, and inhibition of muscle ChE and brain AChE activities at 250 mg/L. No relevant alterations in any of the other tested parameters were found. These results show that carbofuran induced adverse effects on fish by interfering with neurofunction, capability of detoxication and swimming velocity. In addition, positive and significant correlations between the swimming velocity and (i) brain AChE activity, (ii) muscle ChE activity and (iii) EROD activity suggest that the inhibition of these enzymes may somehow be related to the behavioural changes observed. Since these functions are determinant for the survival and performance of the fish in the wild, the findings of the present study suggest that adverse effects may occur in populations exposed to carbofuran if a sufficient number of animals is affected.

- by Lucia Guilhermino
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- Ecotoxicology, Environmental Sciences, Glutathione, Acetylcholinesterase
- by Kamaruzaman Ampon
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- Multidisciplinary, Insecticides, Fruit, Vegetables